I propose continuation of a program of research on the structure of parent-child interaction an on the strategies that family members take within that structure. The current and proposed work is designed to describe in detail the process of parent-child interaction, initially with children between 9 and 22 months. The goal of the research is to describe parent-child interaction systems, permitting comparisons both within and between emphasis on problematic families. The research involves applying to the process of parent-child interaction a well developed set of methodological, descriptive, and conceptual tools for studying face-to-face interaction in general. Included are procedures for transcribing speech (both language and paralanguage) and body motion, for detecting and analyzing patterns of interaction sequences involving these actions, and for describing results. Facilitating the slow process of transcribing interaction and creating data bases will be a system devised here for computer-aided transcribing. Current work focuses on the development of convention-based interaction skills. The goal in this phase of the project is to develop a body of hypotheses concerning the structure and strategy of as many aspects of parent-child interaction as possible. Recent work has focused on parent-child games from 9 to 22 months, child- initiated repair of interaction sequences at 15 and 21 months, and mother-infant feeding at 4 months (based on other tapes). These studies suggest that structural analyses are capable of representing parent-child interaction with considerable subtlety and complexity, permitting detailed comparisons of interactions. Planned studies extend this work to other aspects, such as meals, bath time, and discipline. Concomitantly, work contrasting interaction across families will begin. The purpose of the research is to achieve detailed, specific descriptions of structure and strategy in parent-child interaction that permit higher level statements concerning the nature and complexity of parent-child interaction systems. Detailed description of parent-child interaction may also provide a basic resource for investigators in other developmental areas, such as social cognition, communicative competence, socialization, and the like.